At least in the UK, if I overpay my taxes HMRC will issue a refund.

I can even give them all my tax money, but if I also give them a list of items they deem to be a tax deduction, they will give me my money back. I don't even need to really ask for it except by putting it in the paperwork. I don't need to say "and therefore I believe I have overpaid by £X".